With the arrival of FUD and the ability to have very small clearances between moving parts in one print, to me one obvious application was an attempt at creating the worlds smallest working rubiks cube - the current record stands at 10mm, my cube is 6.2mm and printed in one hit

The spacing (as printed) between the parts is 0.1mm - the spaces are filled with the wax support material. Here's a few of the methods/products I have tried in an attempt to disolve out the wax and free up the parts.

Hot water - the wax melted out, but some of the parts were fused and one part broke - I tried two cubes out using this method, the second broke too.

Alcohol hand sanitiser - this product contains 62% ethanol and seemed to affect both the wax and plastic resulting in some parts stuck together, the central spindles gone soft and broken.

Penetrating oil (WD40 etc) - partial success, but still one of the central spindles broke.

Mineral/white spirit - disolves the wax ok, but also softens the plastic leading to breakage and failure.

Ear Wax Remover - still soaking in this - the remover is quite a viscous fluid at room temperature, and thins qute readily with a bit of heat - this product may work out ok if the temperature can be kept 10-15 celcius above roome temperature (think body heat)

Weak NaOH soultion (caustic soda/lye) - still soaking in this - again this is looking promising

One of the main issues I have with the cubes are the spindles breaking - currently they are 0.7mm diameter - this maybe because I am not waiting long enough before attempting to move the parts.

Hi,
I have had good success with Acetone, which was recommended by the guys at Fineline Prototyping (who also use materials by 3D-Systems).
It does not seem to affect the FUD and resolves the wax. Just be careful with the stuff and use gloves.

Jeroen, thanks for the tip... I think I have some acetone in my garage - and my wife or daughter probably has some nail varnish remover (contains acetone). Also, it just sprung to mind acetone->acetic acid->vinegar - google results show vinegar can be used to dissolve wax

Going back to the original post why should hot water cause any problems ? Fud is a plastic and should not be affected by water. The only reason I can think of is that it was not properly cured in the first place.

I've had items in it sitting in near boiling water for 40 mins at a time without problems while I've been dyeing it.

FUD is acrylic with a softening point lower than boiling water temperature - I think my little cubes failed because the internal parts became deformed and when I tried to move the pieces, they broke... the cubes really are tiny and the wax inside is 0.1mm thick, so surface tension between water & wax is at play too.

I popped a cube in a jar of just boiled water and microwaved it, keeping the water boilng for 5 minutes - after cooling some parts are still solidly joined by wax, and the plastic has gone from transparent to a milky white.

Of all of the things I've tried so far, ear wax remover is ahead, but it does need to be kept at a constsant temperature to thin enough to work on the wax, and yes it has been days now that one cube has been in the remover.

Ah OK I've always kept my water just below boiling point , I've noticed even WSF gets quite soft as at that point.

Have you tried mechanical means, like an ultrasonic cleaner? I've got one and find it wonderful for crud out of places you can't easily get to. Look for a friendly dental lab or jeweler near you as they almost certainly have one.

I have tried nail varnish remover (with castor oil) diluted in water with my level-4 menger cube. I dipped it during a couple of hours, but only some superficial holes were cleaned.

Now I'm trying again with Tetrachloroethylene (also called Perchloroethylene), used in dry cleaning of fabrics and to degrease metal parts. The first time I had previously dipped the model in dish soap, and only checked the cleanness of the holes when the model was wet, although I think this method didn't go deep. I'm saying all of this because after using Tetrachloroethylene, the holes seemed uncleaned when wet, but when dried the wax was missing (0.3mm holes). Now FUD looks white, but not transparent, although maybe the complexity of the Menger model makes difficult to see any transparency. I could check this with a simpler FD model that shows some transparency.

Now for the second try I'm using the model used for the nail varmish remover test. I have also diluted the tetrachloroethylene in water, although this substance has low solubility and sinks to the bottom. In the first try I stirred the mix a couple of times during 2-3 hours. In this second try I've stirred once and I'll check the result after 8-10 hours (left at home).

Definitely, tetrachloroethylene removes the wax but it must be used purely or stirring when mixed with water, and in less than 1-2 hours. The problem is the material gets really "white frosted" once dried, as when very cold metal condenses the water vapour in air. I've tested that with a FD model and only the flattest surfaces doesn't get white (only in the printed lines) while curved surfaces get fully white as White Detail material got dyed with tea on curved surfaces.

I kept checking a cube in the nail varnish remover, after 24 hours, there was still wax between about a 1/3rd of the parts, the last time I lifted the cube out, all the bits that were free of wax fell apart.

has anyone tried Hydrogen Peroxide yet? None of my FUD models have wax on them, so i can't try it myself but i have more complex models coming and am curious if anyone has attempted it... i've noticed that it seems to work better than ear wax remover at removing earwax, and it is much thinner.

Peroxide: I've tried sitting a smelly yellow "waxy" FUD model in room-temperature peroxide for a couple of days, but it did nothing.

Tried earwax remover (peanut oil with alcohol), and dunked the thing in hot water, the oil that came up to the surface was "yellowy", so some wax had been removed. After repeated dunking in boiling water, alcohol, peroxide and anything else I had to hand in various combinations, the holes in my weeny 4-G Menger sponge have opened up, but the crinkly fractal snowflake sponge is still very yellow. I'll have to give acetone a go.

To be fair, the snowflake sponge is probably a worst-case scanario, the 3cm 4-Gen Menger sponge was pretty pale (just a little smelly), but the snowflake sponge was almost lemon-yellow. That was with about two hundred thousand faces, most at right-angles to their neighbours, and all sorts of voids with multiple pinhole openings, so the surface area and surface tension for coatings on it must be horrendous
I'm sure that normal models are fine in FUD. Actually, I don't mind the smallest holes not all being totally clear (they're so small that it's difficult for people to tell), I'm more interested in getting rid of the colour and the odour with these "jaggy" fractal shapes.

To be fair, the snowflake sponge is probably a worst-case scanario, the 3cm 4-Gen Menger sponge was pretty pale (just a little smelly), but the snowflake sponge was almost lemon-yellow.

I had forgotten to post an image after the cleaning with tetrachloroethylene. As I said, the wax disappeared but the material got white on the surface (the holes are 0.3mm wide). The whitening isn't a problem in this model, so many small details makes difficult to see any transparency, but for other models will be surely a problem and tetrachloroethylene has been classified as probably carcinogenic to humans.

- The first one is the slowest and consists of putting the FUD model over a paper on a warm ambient (over the router or through the warm air expelled by the computer's power supply fan). The liquified wax gets trapped on the paper, so it must be replaced by a new clean one periodically. After several hours only some clean holes were visible so this method requires a lot of time but is the less aggressive.

- The second one is quicker and uses white spirit (Stoddard solvent), the solvent used in painting. All the holes got clean and the material didn't got white as happened with tetrachloroethylene, but I'm not sure if it affects in another way the surface of FUD/FD objects (no more FD models at hand). Could anyone test white spirit on flat and curved surfaces?.

The white stuff is actually part of the build. It happens when there is an interface between the plastic and the wax support material. See this photo http://www.shapeways.com/forum/index.php?t=getfile&id=89 44&private=0. You can see there is a little trail of white beneath each column of bolt heads where the was has supported the surface detail. Sometimes if you run your finger nail over the model surface you can feel that the white part is slightly raised.
The only way I have found to deal with it is by abrasion, either with a glass brush or by burnishing the surface with a wooden stick.

I've had this issue myself and I've been doing quite a bit of thinking on how to address it.

It seems to me that the method that would likely be used in a full production environment would either be a solvent specifically formulated for the support wax, or a heating proccess at a controlled temperature to melt the wax from the part.

Now without knowing the specific formulation of the support wax our best bet would be to do the baking method. The difficulty comes with the fact that most ovens aren't designed to heat slowly over a long period of time.

And then it hit me one morning, every one of us has a low temperature, slow heating oven. Our car dashboard.

So I tossed my waxy parts onto a shop towel on my dashboard one morning after I got to work. By lunchtime most of the wax had melted into the towel. I shuffled the parts a bit to free some support wax that wasn't draining properly and by the time my workday was over, a good 80-90% of the yellow wax was gone.

The parts were a bit softer while warm, but returned to normal once cool.

Now my parts didn't have a whole lot of nooks and crannies so YMMV, but with proper orientation for wax drainage this method -should- work for most designs.

The main concern would be to keep the parts from getting -too- hot and warping, but just cracking your car window open a bit can help mitigate the higher temperatures.

Well, after a very long time soaking in earwax remover, my 3x3x3 puzzle cube is still not working, all of the wax is soft enough that the parts that aren't fused are free. As you can see from the image below, there's only 2 parts fused, unfortunately they are center pieces and there's no way around the situation apart from making a slightly bigger cube.

I've yet to try what cleaning method works best (my order is still not in) but from the sound of it I could give my putty oven a try. I made it for curing epoxy putty at a constant temperature (normally between 60-76 centigrade) but it could be turned lower. Though it will still be warmer than the dashboard or router.

I am thinking of printing a functioning bolt and nut assembly together(in the tightened position), with perhaps a 0.1-0.2 mm clearance between the threads. After I receive the print, I want to be able to unscrew the bolt for final cleaning, and be able to put it back and tighten it down.

The bolt diameter will be about 6mm, and length about 10mm. Based on the comments in this thread, I'm pretty sure I won't be able to get all the wax out from between the threads prior to unscrewing the assembly, but will it be possible to use the wax as a lube to facilitate the removal process?

Just my opinion but personnally, if the bolt has to be removed, I would be printed apart (in the same file, but not in its final position). If it has not to be removed I would fuse it with the rest of the design.
Printing in place a part that can be removed is just adding extra risks to the print...
But if it's a custumer request...

I've tried hot water and fairy liquid dunking for several hours, but the model is still decidedly yellow and smelling of the lemony wax material (to my nose). I'm going to try the car/towel/dashboard idea tomorrow, assuming it's sunny

I've removed the wax completely by dunking the pieces in a commercial degreaser, the sort sold in car shops for cleaning engines. But be warned: the removing the wax will reveal a spongy surface where the plastic and wax were laid down next to each other.

Thanks Bill, Stop4 for the further techniques. Leaving to heat up on the car dashboard worked well yesterday and it's definitely less yellowy now. 28 DegsC on my read out when I got back in the car after work. Grey rainy day in the UK today, so no further heating today.

Thanks for the update Mitchell. I was wondering whether the FUD wax situation would improve at the production end or whether it would be an issue to have fellow enthusiasts buy items with the wax, so this puts our minds at rest. My part came through in "The Rush" period a month or more back, so maybe the heating process wasn't quite in place to get models out of the door quicker (perfectly understandable).

Any specific type of baby shampoo you would recommend, and how to use it?

I received a lot of models that were coated with a crystalline lemon yellow wax. I've tried soaking them in boiling water, and wiping them with a variety of solvents, like acetone. These techniques work okay. The acetone has worked the best, but still doesn't help out when the wax is stuck inside the model. The downside of this is its not perfect, and there's still yellow crud in inside my models, and I've just exposed myself to nasty chemicals that I wanted to avoid in the first place.

just did the test with the putty oven and it works like a charm. I've got it at a constant 55 degrees centigrade and the wax melts nicely. Very easy to rub away in a few minutes. Think I found my method for wax removing.

@Ming-Hua, do you know if your method also gets the wax off the surface ready for painting?

I picked up an ultrasonic cleaner the other day and was testing that out with different detergents (Johnson's Baby Shampoo, JPL Sea Clean & ordinary wahing-up liquid), but the cleaner broke so I'm waiting on the replacement. The cleaner was able to get most of the yellow staining though.